Note
Go to the end to download the full example code.
Ship drift
from datetime import datetime
from opendrift.models.shipdrift import ShipDrift
o = ShipDrift(loglevel=20)
o.add_readers_from_list([
'https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml',
'https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc',
'https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml'
])
10:34:40 INFO opendrift:576: OpenDriftSimulation initialised (version 1.14.8 / v1.14.8-2-g680a748)
Seed ship elements at defined position and time Note: beam/length ratio is larger than allowed, but is then clipped internally
o.seed_elements(lon=5.0, lat=63.0, radius=1000, number=1000,
time=datetime.now(),
length=80.0, beam=20.0, height=9.0, draft=4.0)
10:34:40 WARNING opendrift.models.shipdrift:181: Ratio of beam to length should be in range 0.12 to 0.18, given range is 0.25-0.25. Using border value.
10:34:40 INFO opendrift.models.basemodel.environment:203: Adding a global landmask from GSHHG
10:34:45 INFO opendrift.models.basemodel.environment:227: Fallback values will be used for the following variables which have no readers:
10:34:45 INFO opendrift.models.basemodel.environment:230: sea_surface_wave_stokes_drift_x_velocity: 0.000000
10:34:45 INFO opendrift.models.basemodel.environment:230: sea_surface_wave_stokes_drift_y_velocity: 0.000000
10:34:45 INFO opendrift.models.basemodel.environment:230: sea_surface_wave_significant_height: 0.000000
10:34:45 INFO opendrift.models.basemodel.environment:230: sea_surface_wave_mean_period_from_variance_spectral_density_second_frequency_moment: 0.000000
Running model
o.run(steps=24, stop_on_error=True)
10:34:45 INFO opendrift:1821: Storing previous values of element property lon because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
10:34:45 INFO opendrift:1821: Storing previous values of element property lat because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
10:34:45 INFO opendrift:952: Using existing reader for land_binary_mask to move elements to ocean
10:34:45 INFO opendrift:982: All points are in ocean
10:34:45 INFO opendrift:2118: 2026-01-22 10:34:40.680052 - step 1 of 24 - 1000 active elements (0 deactivated)
10:34:45 INFO opendrift.readers:63: Opening file with xr.open_dataset
10:34:49 INFO opendrift.readers.reader_netCDF_CF_generic:332: Detected dimensions: {'x': 'x', 'y': 'y', 'time': 'time'}
10:34:49 INFO opendrift.readers:63: Opening file with xr.open_dataset
10:34:49 INFO opendrift.readers.reader_netCDF_CF_generic:332: Detected dimensions: {'time': 'time', 'x': 'x', 'y': 'y'}
10:34:49 INFO opendrift.readers:63: Opening file with xr.open_dataset
10:34:53 INFO opendrift.readers.reader_netCDF_CF_generic:332: Detected dimensions: {'y': 'rlat', 'x': 'rlon', 'time': 'time'}
10:34:55 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:34:55 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:34:55 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:34:55 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:34:56 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:34:56 INFO opendrift:2118: 2026-01-22 11:34:40.680052 - step 2 of 24 - 1000 active elements (0 deactivated)
10:34:57 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:34:57 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:34:58 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:34:58 INFO opendrift:2118: 2026-01-22 12:34:40.680052 - step 3 of 24 - 1000 active elements (0 deactivated)
10:34:59 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:34:59 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:34:59 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:34:59 INFO opendrift:2118: 2026-01-22 13:34:40.680052 - step 4 of 24 - 1000 active elements (0 deactivated)
10:35:01 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:01 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:01 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:01 INFO opendrift:2118: 2026-01-22 14:34:40.680052 - step 5 of 24 - 1000 active elements (0 deactivated)
10:35:02 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:02 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:03 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:03 INFO opendrift:2118: 2026-01-22 15:34:40.680052 - step 6 of 24 - 1000 active elements (0 deactivated)
10:35:04 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:04 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:05 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:05 INFO opendrift:2118: 2026-01-22 16:34:40.680052 - step 7 of 24 - 1000 active elements (0 deactivated)
10:35:06 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:06 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:07 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:07 INFO opendrift:2118: 2026-01-22 17:34:40.680052 - step 8 of 24 - 1000 active elements (0 deactivated)
10:35:08 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:08 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:09 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:09 INFO opendrift:2118: 2026-01-22 18:34:40.680052 - step 9 of 24 - 1000 active elements (0 deactivated)
10:35:10 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:10 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:10 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:10 INFO opendrift:2118: 2026-01-22 19:34:40.680052 - step 10 of 24 - 1000 active elements (0 deactivated)
10:35:12 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:12 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:12 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:12 INFO opendrift:2118: 2026-01-22 20:34:40.680052 - step 11 of 24 - 1000 active elements (0 deactivated)
10:35:14 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:14 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:14 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:14 INFO opendrift:2118: 2026-01-22 21:34:40.680052 - step 12 of 24 - 1000 active elements (0 deactivated)
10:35:15 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:15 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:16 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:16 INFO opendrift:2118: 2026-01-22 22:34:40.680052 - step 13 of 24 - 1000 active elements (0 deactivated)
10:35:17 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:17 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:18 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:18 INFO opendrift:2118: 2026-01-22 23:34:40.680052 - step 14 of 24 - 1000 active elements (0 deactivated)
10:35:20 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:20 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:21 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:21 INFO opendrift:2118: 2026-01-23 00:34:40.680052 - step 15 of 24 - 1000 active elements (0 deactivated)
10:35:22 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:22 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:23 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:23 INFO opendrift:2118: 2026-01-23 01:34:40.680052 - step 16 of 24 - 1000 active elements (0 deactivated)
10:35:24 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:24 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:24 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:24 INFO opendrift:2118: 2026-01-23 02:34:40.680052 - step 17 of 24 - 1000 active elements (0 deactivated)
10:35:26 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:26 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:26 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:26 INFO opendrift:2118: 2026-01-23 03:34:40.680052 - step 18 of 24 - 1000 active elements (0 deactivated)
10:35:28 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:28 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:28 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:28 INFO opendrift:2118: 2026-01-23 04:34:40.680052 - step 19 of 24 - 1000 active elements (0 deactivated)
10:35:29 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:29 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:30 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:30 INFO opendrift:2118: 2026-01-23 05:34:40.680052 - step 20 of 24 - 1000 active elements (0 deactivated)
10:35:31 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:31 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:32 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:32 INFO opendrift:2118: 2026-01-23 06:34:40.680052 - step 21 of 24 - 1000 active elements (0 deactivated)
10:35:33 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:33 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:34 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:34 INFO opendrift:2118: 2026-01-23 07:34:40.680052 - step 22 of 24 - 1000 active elements (0 deactivated)
10:35:35 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:35 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:36 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:36 INFO opendrift:2118: 2026-01-23 08:34:40.680052 - step 23 of 24 - 1000 active elements (0 deactivated)
10:35:37 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:37 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:38 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
10:35:38 INFO opendrift:2118: 2026-01-23 09:34:40.680052 - step 24 of 24 - 1000 active elements (0 deactivated)
10:35:39 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:39 WARNING opendrift.readers.interpolation.structured:63: Ensemble data currently not extrapolated towards seafloor
10:35:40 INFO opendrift.models.shipdrift:311: Using Stokes drift direction as wave direction
Print and plot results
print(o)
o.plot(linecolor='orientation')
#o.animation(color='orientation', markersize=20, filename="orientation.gif", legend=['left','right'],colorbar=False,cmap='bwr')
o.animation(color='orientation', legend=['left','right'], markersize=20, colorbar=False, cmap='bwr')

===========================
--------------------
Reader performance:
--------------------
global_landmask
0:00:00.0 total
0:00:00.0 preparing
0:00:00.0 reading
0:00:00.0 masking
--------------------
https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml
0:00:15.3 total
0:00:00.0 preparing
0:00:15.2 reading
0:00:00.0 interpolation
0:00:00.0 interpolation_time
0:00:00.0 rotating vectors
0:00:00.0 masking
--------------------
https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc
0:00:16.9 total
0:00:00.0 preparing
0:00:16.9 reading
0:00:00.2 interpolation
0:00:00.0 interpolation_time
0:00:00.0 rotating vectors
0:00:00.0 masking
--------------------
https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml
0:00:13.2 total
0:00:00.0 preparing
0:00:13.2 reading
0:00:00.0 interpolation
0:00:00.0 interpolation_time
0:00:00.0 rotating vectors
0:00:00.0 masking
--------------------
Performance:
59.7 total time
4.5 configuration
0.0 preparing main loop
0.0 moving elements to ocean
55.1 main loop
0.4 updating elements
0.0 cleaning up
--------------------
===========================
Model: ShipDrift (OpenDrift version 1.14.8)
1000 active ShipObject particles (0 deactivated, 0 scheduled)
-------------------
Environment variables:
-----
land_binary_mask
1) global_landmask
-----
x_sea_water_velocity
y_sea_water_velocity
1) https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml
2) https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml
-----
x_wind
y_wind
1) https://thredds.met.no/thredds/dodsC/mepslatest/meps_lagged_6_h_latest_2_5km_latest.nc
-----
sea_surface_wave_mean_period_from_variance_spectral_density_second_frequency_moment
sea_surface_wave_significant_height
sea_surface_wave_stokes_drift_x_velocity
sea_surface_wave_stokes_drift_y_velocity
1) https://thredds.met.no/thredds/dodsC/cmems/mywavewam3km/dataset-wam-arctic-1hr3km-be.ncml
Discarded readers:
Time:
Start: 2026-01-22 10:34:40.680052 UTC
Present: 2026-01-23 10:34:40.680052 UTC
Calculation steps: 24 * 1:00:00 - total time: 1 day, 0:00:00
Output steps: 25 * 1:00:00
===========================
10:35:53 INFO opendrift:4667: Saving animation to /root/project/docs/source/gallery/animations/example_shipdrift_0.gif...
10:36:07 INFO opendrift:3101: Time to make animation: 0:00:14.704873
Total running time of the script: (1 minutes 34.199 seconds)